This invention relates to organic particulate-filled adhesives containing ionomeric particulate and a polymer matrix. The ionomeric particulates are made from a suspension polymerization process. Depending on the particular ionomeric particulate composition and the particular polymer matrix, a wide variety of adhesives can be formulated. Particularly useful adhesives include repulpable adhesive and cosmetic adhesive.
Adhesives have been made using beads made from suspension polymerization. For example, U.S. Pat. No. 5,952,420 (Senkus et al.) discloses permeable, self-supporting shaped structures that can be used in applications such as filters, masks, or respirators. The structure comprises a mass of active particulate (e.g., sorbents such as activated carbon, silica gel, or alumina (granules) bonded together with pressure sensitive adhesive polymer particulates (also referred to as xe2x80x9cPSA suspension beadsxe2x80x9d).
Adhesives have been formulated for application to skin for consumer cosmetic needs, such as skin cleansing or moisturizing. For example, U.S. Pat. No. 5,723,138 (Bae et al.) discloses a cosmetic composition having adhesive properties useful for alleviating wrinkles or furrows on skin. The composition is prepared by coating active ingredients comprising vitamin A, vitamin E, and aloe extract together with an adhesive on a non-toxic carrier.
U.S. Pat. No. 5,512,277 (Uemura et al.) discloses a keratotic plug remover composition and a method for removing keratotic plugs from the skin. Others skilled in the art have pursued different avenues to remove keratotic plugs, such as those disclosed in U.S. Pat. No. 5,939,093 (Park et al.). Other references that disclose keratotic plug removers include WO 98/06375, WO 98/05283, and WO 97/32567.
U.S. Pat. No. 5,935,596 (Crotty et al.) discloses a cosmetic product that delivers skin actives (such as vitamins, herbal extracts, alpha- and beta-hydroxycarboxylic acids, etc.) through adhesive strips. The strips can concurrently remove keratotic plugs from skin pores. The cosmetic product includes an adhesive polymer that may either be anionic, cationic, nonionic, amphoteric, zwitterionic, or mixtures thereof.
U.S. Pat. No. 5,512,612 (Brown et al.) discloses a pressure sensitive adhesive comprising a blend of (a) a polymeric, elastomeric, solvent insoluble but solvent dispersible microparticle component; and (b) a water-dispersible polymeric component. The adhesive is repulpable when tested according to TAPPI test UM-213.
While the foregoing adhesives may be useful for their intended applications, other adhesive compositions are sought.
This invention provides novel organic particulate-filled adhesives. The adhesives can be formulated for various applications, such as for cosmetic applications and for repulpable adhesive applications. In brief summary, the organic particulate-filled adhesive comprises ionomeric particulates dispersed in a polymer matrix containing water-soluble polymer or water-dispersible polymer. The polymer matrix functions as a continuous phase binding the ionomeric particulates together. Additional components can be added to the adhesive including, but not limited to, plasticizers, opacifying agents, skin conditioning agents, and skin cleansing agents. In one embodiment of the invention, the adhesive contains at most about 40 parts by weight of a plasticizer commonly referred to as a xe2x80x9ctackifierxe2x80x9d (based on the polymer matrix weight), in which case the adhesive is particularly useful as a cosmetic adhesive. In another embodiment of the invention, the adhesive contains at least 40 parts by weight of a plasticizer (based on the polymer matrix weight that is a water-soluble polymer), in which case the adhesive is particularly useful as a repulpable adhesive.
In a cosmetic application, a user, i.e., a consumer, typically wets the skin where cleaning is desired and applies a cosmetic strip containing the inventive adhesive coated to a backing. Alternatively, the user wets the cosmetic strip with a small amount of water and applies the moistened strip to the skin. In a cosmetic strip application, it is the exposure of the organic particulate-filled adhesive to water that gives it pressure-sensitive adhesive properties. After a duration of time, which can range from about 1 to 20 minutes, the user pulls the strip away from the skin thereby removing unwanted matter such as comedomes, unwanted hair follicles, dirt, oil, dead skin, and debris. In a repulpable adhesive application, the inventive adhesive preferably does not interfere with the paper manufacturing process. Also, the adhesive components are preferably dispersed in the paper to minimize defects.